package com.csa.video;

import java.io.IOException;
import java.util.List;

import android.content.Context;
import android.hardware.Camera;
import android.hardware.Camera.Size;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

public class TestVideoPreview extends SurfaceView implements SurfaceHolder.Callback 
{

    SurfaceHolder mHolder;
    Camera mCamera;
    Camera.PreviewCallback previewCallback;
    boolean created = false;

	public TestVideoPreview(Context parent, Camera.PreviewCallback previewCallback)
	{
		super(parent);
        this.previewCallback = previewCallback;

        // Install a SurfaceHolder.Callback so we get notified when the
        // underlying surface is created and destroyed.
        mHolder = getHolder();
        mHolder.addCallback(this);
        mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
        mCamera = Camera.open();
        try {
            mCamera.setPreviewDisplay(mHolder);
         } catch (IOException exception) {
             mCamera.release();
             mCamera = null;
             // TODO: add more exception handling logic here
         }
        Camera.Parameters parameters = mCamera.getParameters();

        List<Size> sizes = parameters.getSupportedPreviewSizes();
        Size optimalSize = getOptimalPreviewSize(sizes, 352, 288);
        parameters.setPreviewSize(optimalSize.width, optimalSize.height);

        mCamera.setParameters(parameters);
        if (previewCallback != null) {
            mCamera.setPreviewCallback(previewCallback);
        }
        mCamera.startPreview();
        created = true;
    }

    public void surfaceCreated(SurfaceHolder holder) {
    	if (created) return;
        // The Surface has been created, acquire the camera and tell it where
        // to draw.
        mCamera = Camera.open();
        try {
           mCamera.setPreviewDisplay(holder);
        } catch (IOException exception) {
            mCamera.release();
            mCamera = null;
            // TODO: add more exception handling logic here
        }
    }

    public void surfaceDestroyed(SurfaceHolder holder) {
        // Surface will be destroyed when we return, so stop the preview.
        // Because the CameraDevice object is not a shared resource, it's very
        // important to release it when the activity is paused.
        mCamera.stopPreview();
        mCamera.release();
        mCamera = null;
        created = false;
    }


    private Size getOptimalPreviewSize(List<Size> sizes, int w, int h) {
        final double ASPECT_TOLERANCE = 0.05;
        double targetRatio = (double) w / h;
        if (sizes == null) return null;

        Size optimalSize = null;
        double minDiff = Double.MAX_VALUE;

        int targetHeight = h;

        // Try to find an size match aspect ratio and size
        for (Size size : sizes) {
            double ratio = (double) size.width / size.height;
            if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE) continue;
            if (Math.abs(size.height - targetHeight) < minDiff) {
                optimalSize = size;
                minDiff = Math.abs(size.height - targetHeight);
            }
        }

        // Cannot find the one match the aspect ratio, ignore the requirement
        if (optimalSize == null) {
            minDiff = Double.MAX_VALUE;
            for (Size size : sizes) {
                if (Math.abs(size.height - targetHeight) < minDiff) {
                    optimalSize = size;
                    minDiff = Math.abs(size.height - targetHeight);
                }
            }
        }
        return optimalSize;
    }

    public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
        // Now that the size is known, set up the camera parameters and begin
        // the preview.
        Camera.Parameters parameters = mCamera.getParameters();

        List<Size> sizes = parameters.getSupportedPreviewSizes();
        Size optimalSize = getOptimalPreviewSize(sizes, w, h);
        parameters.setPreviewSize(optimalSize.width, optimalSize.height);

        mCamera.setParameters(parameters);
        if (previewCallback != null) {
            mCamera.setPreviewCallback(previewCallback);
//            Camera.Size size = parameters.getPreviewSize();
//            byte[] data = new byte[size.width*size.height*
//                    ImageFormat.getBitsPerPixel(parameters.getPreviewFormat())/8];
//            mCamera.addCallbackBuffer(data);
        }
        mCamera.startPreview();
    }
}
